Apparatus for burnishing straight cylindrical surfaces and for rolling crankshaft fil



O. L CORY ETAL SURFACES AND FOR ROLLING CRANKSHAFT FILLE'I'S APPARATUS FOR BURNISHING STRAIGHT CYLINDRICAL Nov. 8, 1966 Filed April 30, 1965 INVENTORS DALE E. BOWMAN ODA L. CORY ATTORNEY NOV. 8, 1966 co ETAL 3,283,393

APPARATUS FOR BURNISHING STRAIGHT CYLINDRICAL SURFACES AND FOR ROLLING CRANKSHAFT FILLETS Filed April 50, 1965 2 Sheets-Sheet 2 w & INVENTORS DALE E. BOWMAN l9 ODA L.CORY

TORNEY United States Patent 3,283,393 APPARATUS FOR BURNISHING STRAIGHT CY- LINDRICAL SURFACES AND FOR ROLLING CRANKSHAFT FILLETS Oda L. Cory, 1168 Indian Creek Road, and Dale E. Bowman, 142 S. Traub Ave., both of Indianapolis, Ind. Filed Apr. 30, 1965, Ser. No. 452,092

9 Claims. (Cl. 29-90) The present invention relates to an improved apparatus for metal working and more particularly to an apparatus for burnishing straight cylindrical surfaces and for rolling fillets on a crankshaft or the like.

In crankshafts, it is desirable to burnish the bearing surfaces of the crankshaft so that the outer surface is smooth and hard to an accurate finished dimension. Also, it is desirable to provide annular fillets at opposite ends of bearing or journal portions where they are connected to the counterweights of the crankshaft. The burnishing operation and the rolled fillets provide for a strengthened crankshaft which will not be prone to fractures or cracking and which better resists deformation in use.

An important object of the present invention is the provision of an apparatus which will simultaneously provide a burnishing action of the straight cylindrical bearing surfaces and also roll the annular fillets at the opposite ends of the bearing surface. The apparatus requires a minimum number of rollers for both burnishing and rolling fillets in a simplified frame which may be attached to and the crankshaft rotated by a lathe or other turning equipment. 7

Heretofore, it has not been possible to provide a simple arrangement for simultaneously burnishing the journal and rolling the fillets of a crankshaft for'the reason that the fillet rolling mechanism is not strong enough to serve as a reaction point for the high degree of pressure required for effective burnishing. According to our invention, we have overcome this problem and at the same time have provided a more effective fillet rolling mechanism.

Another object of the present invention is the provision of a burnishing and fillet rolling apparatus having a burnishing roller and substantially diametrically opposite therefrom a pair of fillet rollers; both the burnishing roller and the fillet rollers being free-floating in a supporting frame. The simultaneous burnishing and rolling action is capable of reducing both cylindrical bearing journals and circular fillets in an extremely rapid time cycle.

A further object of the present invention is the provision of a free-floating burnishing roller which is backed up by a pair of anti-friction rollers forming a complete solid or rigid assembly when pressure is introduced onto the bearing surface through the burnishing roller. Also, a pair of free-floating angular radii rollers roll the annular fillets and these rollers are also backed up by a pair of anti-friction rollers forming a complete solid assembly when presure is introduced through the opposite burnishing roller. The burnishing roller is of a small diameter to easily penetrate and burnish the workpiece and the pressure of the fillet rollers occurs at an angle of 45 relative to the bearing journal.

The present invention also comprehends the provision of a burnishing and fillet rolling apparatus which utilizes mechanical pressure provided by a mechanical advantage due to the placement of the rolls substantially diametrically in line with the crankshaft journal so as to impart a crushing pressure resulting in a much more compacted and finer or more accurate finish. The pressure is caused by the two sets of rollers being arranged closer together than the diameter of the work to be burnished.

The present invention further comprehends the provision of a burnishing and fillet rolling apparatus where the size adjustmentjand mechanical pressure adjustment of the rollers are provided through an eccentrically mounted axle which supports the lower roller cage for the burnishing roller. This axle may be locked in any adjusted position through a lock nut.

A further object of the present invention is the provision of a mounting bracket which may be secured to the bed of lathe or other turning equipment and carrying a floating main C-fame holder for the burnishing and fillet rollers. The floating main frame is utilized to compensate for any irregular motion of the crankshaft during rotation for the burnishing and fillet rolling operation.

These and further objects will become more readily apparent from the following description when considered in connection with the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of the burnishing and fillet rolling apparatus showing the device attached to a section of a crankshaft.

FIG. 2 is a top plan view of the apparatus of FIG. 1 with the crankshaft removed.

FIG. 3 is a front elevational view partially in vertical cross section taken on the irregular line 33 of FIGfl.

FIG. 4 is a vertical cross sec-tion taken on the line 4-4 of FIG. 1. 'Y

FIG. 5 is an enlarged vertical cross sectional View taken on the line 5--5 of FIG. 1 and more clearly showing the burnishing and fillet rollers in operative position on a section of a crankshaft.

Referring more particularly to the drawings in which is disclosed an illustrative embodiment of the present invention, FIG. 1 discloses a burnishing and fillet rolling device having a mounting bracket 10 with a base 11 and a pair of spaced parallel and vertically arranged side members 12; reinforcing ribs 13 being welded to the base 11 and side members 12. A main holder 14 is mounted between and within the side members 12 and is provided with floating action through a fulcrum 15 extending through aligned openings in the side members 12 and hollder 14 (see FIG. 4). The opening in the main holder 14 is enlarged to receive a bearing sleeve 16 which closely encompasses the fulcrum 15. A set screw retains the fulcrum in the members 12.

The floating action of the main frame or holder 14 is limited by a safety pin 17 which extends through aligned openings in the side members 12 and through an enlarged opening 18 in the holder 14. The opening 18 receives a width spacer sleeve 19 conformab'ly fitting in opening 18 but of a larger internal diameter than the diameter of the safety pin 17. The limit of the floating action is the dif ference between the internal diameter of sleeve 19 and the outer diameter of the safety pin 17.

The main holder 14 has the general configuration of a C-frame with an upper arm 21 and a lower arm 22. The upper arm 21 is provided with a depending portion 23 of reduced width providing a roller cage 24. The roller cage 24 is provided with a pair of horizontally spaced back-up .antifr-iction rolls 25, each roll revolving on an axle 26 retained in the cage by lock rings 27 and including a bearing sleeve 28 mounted on the axle 26 and a plurality of roller bearings 29 between the sleeve and the outer roll 25. A vertical slot 31 extends partially through the arm 21 opening at the top and front edge of the arm; a

ridge. The retainer pins 35 are not axles for the rollers 36 but leave the rollers loose and free to find their location between the back-up rolls 26 and the workpiece W. FIG. clearly shows the rollers 36 positioned for rolling ,the fillets 38 at the opposite ends-of the bearing surface 39 on the workpiece W.

l Thelower ar'm 22 is bifurcated at '41 (FIG. 3) and provides'space for receiving therebetween an adjustable lower roller 'cage 42'. This roller cage also is provided with a pair ofliorizontatlily spaced anti-friction rollers 43, eacl1 roller rotating on an axle 44. The anti-friction rollers 43 are substantially the same in construction as the rolls'25 with a bearing sleeve 45 on the axle 44and a plurality of rollerbearings 46 supporting the roller 43. A burnishing roller 47 is backed up by the anti-friction rollers 43, and

these rollers are all held in place by a pair of side plates 48" suitably secured to the roller cage 42 by bolts 49 or similar securing means. The burnishing roller 47 utilized is of a diameter which istoo small to run on an axle and both the burnishing roller and the axles 44 of the anti-friction rollers" 43 are provided without outward support. .The burnishing roller 47 is so arranged in the system to take the extreme pressures of the burnishing-Without an axle while the burnishing roller remains in an anti-friction condition.

Size adjustment and pressure adjustment for the workpiece are accomplished by moving the lower roller cage 42' closer to or farther away from the fillet rollers 36 which are positioned substantially diametrically opposite the burnishing roller 47. To accomplish movement of the roller cage 42, a tapered eccentric lock pin 51 is mounted in openings in the bifurcated portion 41 of the lower arm 22. The lock pin includes a reduced cylindrical portion 52 adjacent one end and an aligned tapered portion .53 adjacent the other end; the tapered portion terminating in a head 54 for a turning tool. The cylindrical portion 52 terminates in a threaded end 55 for receiving a lock nut 56. The opening in the arm receiving the tapered portion 53 has a complementary taper to provide a clamping action with the lock nut to retain the lock pin in adjusted position. Between the portions 52 and 53 is an eccentrically mounted cylindrical portion 57 received in a complementary opening in the lower roller cage 42. Thus,rotation of the lock pin 51 rotates the eccentrically mounted portion 57 to raise or lower the cage 42.

According to our invention, it is possible to develop a high degree of pressure for the reason that the fillet rollers 36 are backed up by the rolls 25, the pressure thus being f transmitted from the back-up rolls 25 to the fillets through the entire body of the filletrollers, as contrasted with transmissionof pressure through an axle. Furthermore, the fillet rollers 36 in their entirety provide a toggle action which is extremely effective in rolling the fillets for the reason that the fillet rolling pressure is exerted laterally as well as downwardly.

' The fillet rollers 36 are preferably disposed at a 45 angle with respect to the vertical as shown in FIG. 5. It will be noted that the retainer pins 56 permit selfadjustment of the angular disposition of the fillet rollers asthey work themselves into the fillet being rolled. There- ;fore, pressure is applied directly through the theoretical loci of the radii. I

Similarly, the -use of the back-up arrangement for the gfillet rollers permits one to burnish the cylindrical sur- {face 39 simultaneously. For instance, the pressure exerted by burnishing roller 47 on the surface 39 can be nogreater than the reaction afforded by the oppositely dispo sefdfillet rollers 36. Since our fillet-rolling mechanism is capable of withstanding high burnishing pres- 'LSHIE,'it is possible to use the high mechanical advantage developed by eccentricity 57 of the lock pin 51 to develop a much'higher degree of burnishing and fillet rollingipressure than has previously been accomplished by 4 prior art arrangements, and it also permits burnishing and fillet rolling to be etfected simultaneously.

In operation, the workpiece is placed between the upper roller cage 24 and the lower roller cage 42 and connected to suitable turning equipment, such as a lathe. The lock. nut 56 is loosened and the lock pin 51 rotated to raise the rollercage 42 to exert pressure on the surfaces being rolled. It should be noted that spacer shims may be placed between the shoulders 58 on the lower roller cage 42 and the bifurcated portion 41 of the arm 22 to aid in obtaining the desired compression between the burnishing roller and the fillet rollers. When the lock pin 51 is adjusted, the lock nut 56 is tightened and the workpiece is rotated to burnish the bearing surface and the circular filleted surfaces.- As the burnishing roller 47 is of a small diameter relative to the workpiece, it easily penetrates and burnishes the cylindrical bear-ing surface 39 of the workpiece with a cylindrical burnishing action. The burnishing may be accomplished either wet or dry and the burnishing covers any flat surfaces on the workpiece.

Having disclosed the invention, we claim:

1. An apparatus for simultaneously burnishing straight cylindrical surfaces and circular fillets at the ends thereof, comprising a frame, an upper roller cage and a lower roller cage in said frame, said upper roller cage including a pair of angularly disposed free-floating fillet rollers, and a pair of back-up rolls for the fillet rollers, said lower cage including a burnishing roller and a pair of means to adjust said lower roller cage. to vary the space.

ing between the fillet rollers and the burnishing roller.

2. An apparatus for simultaneously burnishing straight cylindrical surfaces and circular fillets at the ends thereof, comprising a floating generally C-s-haped frame, an upper roller. cage and a lower roller cage in said frame, said upper roller cage including a pair of anti-friction back-up rolls and a pair of angularly disposed free-floating fillet rollers engaging the back-up rolls, said lower roller cage including a pair of anti-friction back-up rollers and a burnishing roller resting upon the back-up roll.- ers, said burnishing roller having a diameter substantially smaller than the diameter of the workpiece being burnished and being positioned substantially diametrically opposite the fillet rollers, and an eccentric lock pin for adjusting the position of the lower roller cage relative to the upper roller cage.

3. An apparatus as set forth in claim 2, in which said upper roller cage includes angularly disposed retainer pins retaining the fillet rollers in the cage, said filletrollers having central passages diverging outwardly from a central-annular ridge to provide free-floating action on said retainer pins.

4. An apparatus as set forth in claim 2, including a mounting bracket adapted to be secured in suitable turning equipment for rotation of the workpiece, said frame being provided with a floating action relative to said bracket.

5.. An apparatus for burnishing straight cylindrical sections and circular fillets at the ends thereof, comprising a generally C-shaped floating frame, an upper roller cage and a lower roller cage in said frame receiving therebetween a workpiece to be burnished, said'upper roller cage including a pair of anti-friction back-up. rolls, a pair of angularly disposed retainer pins below and intermediate said rolls and an angular-1y disposed fillet roller on each retainer pin, each fillet roller received Within a val-. ley formed by the back-up rollers and having a free-float: ing action to.-properly align the rollers inthe fillet areas of the workpiece, said lower roller cage including a pair of anti-friction rollers and a burnishing roller-received in the valley formed by said last mentioned anti-friction rollers, said burnishing roller being of a substantially. smaller diameter than the diameter of the workpiece, said lower roller cage being mounted for reciprocable movement in said frame to vary the spacing between the burnishing and fillet rollers, and an eccentric lock pin rotatably mounted in said frame for reciprocating said lower roller cage upon rotation of said lock pin.

6. An apparatus as set -forth in claim 5, in which said lock pin includes a cylindrical end portion terminating in a threaded end, an eccentric central portion operatively connected to said 'lower roller cage and a tapered end portion terminating in a driving head, and a lock nut engaging the threaded end of the lock pin to retain said lock pin in adjusted position.

7. An apparatus as set forth in claim 5, in which said anti-friction rollers in the lower roller cage are mounted on spaced axles, said last mentioned axles and said burnishing roller extending through the sides of said lower roller cage, and a pair of side plates retaining said axles and burnishing roller Within the roller cage.

8. An apparatus as set forth'in claim 5, including a mounting bracket for said frame, a fulcrum in said mount ing bracket and extending through said frame providing pivotal movement of the frame relative to said mounting bracket, and a safety pin in said mounting bracket, said frame having an opening therein greater in diameter than and receiving said safety pin and cooperating therewith to limit the floating pivotal movement of the frame.

9. An apparatus as set forth in claim 8, in which said mounting bracket is adapted to be mounted in suitable turning equipment to rotate said workpiece.

No references cited.

RICHARD H. EANES, JR., Primary Examiner. 

1. AN APPARATUS FOR SIMULTANEOUSLY BURNISHING STRAIGHT CYLINDRICAL SURFACES AND CIRCULAR FILLETS AT THE ENDS THEREOF, COMPRISING A FRAME, AN UPPER ROLLER CAGE AND A LOWER ROLLER CAGE IN SAID FRAME, SAID UPPER ROLLER CAGE INCLUDING A PAIR OF ANGULARLY DISPOSED FREE-FLOATING FILLET ROLLERS, AND A PAIR OF BACK-UP FOR THE FILLETS ROLLERS, SAID LOWER CAGE INCLUDING A BURNISHIN ROLLER AND A PAIR OF BACK-UP ROLLERS, SAID BURNISHING ROLLER BEING POSITIONED 